Ergodicity breaking and lack of a typical waiting time in area-restricted search of avian predators

Movement tracks of wild animals frequently fit models of anomalous rather than simple diffusion, mostly reported as ergodic superdiffusive motion combining area-restricted search within a local patch and larger-scale commuting between patches, as highlighted by the L\'evy walk paradigm. Since L\'evy walks are scale invariant, superdiffusive motion is also expected within patches, yet investigation of such local movements has been precluded by the lack of accurate high-resolution data at this scale. Here, using rich high-resolution movement datasets ($>\! 7 \times 10^7$ localizations) from 70 individuals and continuous-time random walk modeling, we found subdiffusive behavior and ergodicity breaking in the localized movement of three species of avian predators. Small-scale, within-patch movement was qualitatively different, not inferrable and separated from large-scale inter-patch movement via a clear phase transition. Local search is characterized by long power-law-distributed waiting times with diverging mean, giving rise to ergodicity breaking in the form of considerable variability uniquely observed at this scale. This implies that wild animal movement is scale specific rather than scale free, with no typical waiting time at the local scale. Placing these findings in the context of the static-ambush to mobile-cruise foraging continuum, we verify predictions based on the hunting behavior of the study species and the constraints imposed by their prey.Comment: 27 pages, 8 figure

Diurnal timing of nonmigratory movement by birds: the importance of foraging spatial scales

Timing of activity can reveal an organism's efforts to optimize foraging either by minimizing energy loss through passive movement or by maximizing energetic gain through foraging. Here, we assess whether signals of either of these strategies are detectable in the timing of activity of daily, local movements by birds. We compare the similarities of timing of movement activity among species using six temporal variables: start of activity relative to sunrise, end of activity relative to sunset, relative speed at midday, number of movement bouts, bout duration and proportion of active daytime hours. We test for the influence of flight mode and foraging habitat on the timing of movement activity across avian guilds. We used 64 570 days of GPS movement data collected between 2002 and 2019 for local (non‐migratory) movements of 991 birds from 49 species, representing 14 orders. Dissimilarity among daily activity patterns was best explained by flight mode. Terrestrial soaring birds began activity later and stopped activity earlier than pelagic soaring or flapping birds. Broad‐scale foraging habitat explained less of the clustering patterns because of divergent timing of active periods of pelagic surface and diving foragers. Among pelagic birds, surface foragers were active throughout all 24 hrs of the day while diving foragers matched their active hours more closely to daylight hours. Pelagic surface foragers also had the greatest daily foraging distances, which was consistent with their daytime activity patterns. This study demonstrates that flight mode and foraging habitat influence temporal patterns of daily movement activity of birds.We thank the Nature Conservancy, the Bailey Wildlife Foundation, the Bluestone Foundation, the Ocean View Foundation, Biodiversity Research Institute, the Maine Outdoor Heritage Fund, the Davis Conservation Foundation and The U.S. Department of Energy (DE‐EE0005362), and the Darwin Initiative (19-026), EDP S.A. ‘Fundação para a Biodiversidade’ and the Portuguese Foundation for Science and Technology (FCT) (DL57/2019/CP 1440/CT 0021), Enterprise St Helena (ESH), Friends of National Zoo Conservation Research Grant Program and Conservation Nation, ConocoPhillips Global Signature Program, Maryland Department of Natural Resources, Cellular Tracking Technologies and Hawk Mountain Sanctuary for providing funding and in-kind support for the GPS data used in our analyses

Trajectories all birds (n=14)

Three files:1. The first time each bird was translocated to an unfamiliar area (figure S1). 2. The second time each bird was translocated to a familiar area (figure S1).3. Home range movements

The complex interaction network among multiple invasive bird species in a cavity-nesting community

International audienceAlien invasive species have detrimentaleffects on invaded communities. Aliens do not invadea vacuum, but rather a community consisting of nativeand often other alien species. Our current understandingof the pathways and network of interactions amongmultiple invasive species within whole communities islimited. Eradication efforts often focus on a singletarget species, potentially leading to unexpectedoutcomes on interacting non-target species. We aimedto examine the interaction network in a cavity-nestingcommunity consisting of native and invasive birds.We studied the nesting cavities in the largest urbanpark in Israel over two breeding seasons. We foundevidence for a complex interaction network thatincludes negative, neutral and positive interactions,but no synergistic positive interactions among aliens.Three major factors shaped the interaction network:breeding timing, nesting preferences and the ability toexcavate or widen the cavities, which were found to bea limited resource. Cavity enlargement by the earlybreedinginvasive rose-ringed parakeet may enhancebreeding of the invasive common myna in previouslyunavailable holes. The myna excludes the smallerinvasive vinous-breasted starling, a direct competitorof the primary nest excavator, the native Syrianwoodpecker. Therefore, management and eradicationefforts directed towards the common myna alone mayactually release the vinous-breasted starling fromcompetitive exclusion by the common myna, increasingthe negative impact of the vinous-breasted starlingon the native community. As found here, interactionsamong multiple alien species can be crucial in shapinginvasion success and should be carefully consideredwhen aiming to effectively manage biologicalinvasions

Data from: Novel insights into the map stage of true navigation in non-migratory wild birds (stone curlews, Burhinus oedicnemus)

In the map-and-compass model of true navigation, animals in unfamiliar sites determine their position relative to a destination site (the map stage) before progressing towards it (the compass stage). A major challenge in animal navigation research is to understand the still cryptic map stage in general, and for free-ranging wild animals in particular. To address this challenge, we experimentally translocated wild, non-migratory birds (Stone curlews (Burhinus oedicnemus)) far from their nests and GPS-tracked their subsequent movements at high resolution and for long durations. Homing success was high, and cannot be explained by random chance or landmark navigation, implying true navigation. Although highly motivated to return home, the homing trajectories of translocated birds exhibited a distinct, two-phase pattern resembling the map and compass stages: a long, tortuous "wandering phase" without consistent approach home, followed by a short and direct "return phase". Birds re-translocated to the same site initially repeated the original wandering path but switched to the return phase earlier and after covering a smaller area; they returned home via a different path but with similar movement properties. We thus propose that birds resolve the map by acquiring, and potentially learning, the relevant navigation cues during the wandering phase

Big-data approaches lead to an increased understanding of the ecology of animal movement

Understanding animal movement is essential to elucidate how animals interact, survive, and thrive in a changing world. Recent technological advances in data collection and management have transformed our understanding of animal “movement ecology” (the integrated study of organismal movement), creating a big-data discipline that benefits from rapid, cost-effective generation of large amounts of data on movements of animals in the wild. These high-throughput wildlife tracking systems now allow more thorough investigation of variation among individuals and species across space and time, the nature of biological interactions, and behavioral responses to the environment. Movement ecology is rapidly expanding scientific frontiers through large interdisciplinary and collaborative frameworks, providing improved opportunities for conservation and insights into the movements of wild animals, and their causes and consequences

Big-data approaches lead to an increased understanding of the ecology of animal movement

Nathan R, Monk CT, Arlinghaus R, et al. Big-data approaches lead to an increased understanding of the ecology of animal movement. Science. 2022;375(6582): eabg1780.Understanding animal movement is essential to elucidate how animals interact, survive, and thrive in a changing world. Recent technological advances in data collection and management have transformed our understanding of animal "movement ecology" (the integrated study of organismal movement), creating a big-data discipline that benefits from rapid, cost-effective generation of large amounts of data on movements of animals in the wild. These high-throughput wildlife tracking systems now allow more thorough investigation of variation among individuals and species across space and time, the nature of biological interactions, and behavioral responses to the environment. Movement ecology is rapidly expanding scientific frontiers through large interdisciplinary and collaborative frameworks, providing improved opportunities for conservation and insights into the movements of wild animals, and their causes and consequences